package com.atguigu.springcloud.lb;

import cn.hutool.log.Log;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

@Component
@Slf4j
public class MyLBImpl implements MyLB{

    private AtomicInteger atomicInteger =new AtomicInteger(0);

    public final int getAndIncrement(){
        int current;
        int next;
        do {
            current=this.atomicInteger.get();
            next=current >= 2147483647? 0 :current+1;
        }while (!this.atomicInteger.compareAndSet(current,next));
        log.info("*****next: "+next);
        return next;
    }

    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances) {
        int index=getAndIncrement()%serviceInstances.size();
        return serviceInstances.get(index);
    }
}
